Dec., 1904.] 
Tabanidae. 
225 
contiguous with the hyaline base of the discal cell, the second 
basafcell is hyaline with the exception of a slight infuscation at 
base. The outer border of the cross-band is nearly straight, the 
hyaline triangle is rather small and does not cross the second vein 
and the apical spot fills out the marginal cell and much of the 
first and second submarginal and first posterior cells. The 
abdomen is yellow with two black stripes extending frcm the 
scutellum to the apex and on either side of these another nar- 
rower stripe of the same color extending backward frcm the 
anterior part of the third segment. The type was collected in 
Missouri and I have specimens from Kansas. 
Chrysops proclivis Osten Sacken. Frontal callosity, antennae, 
each facial callosity outside of the suture and cheeks black. First 
basal cell of the wing black for its entire length in the middle but 
near the apex on either side next the longitudinal veins there is 
some hyaline, the second basal is hyaline, the outer margin of the 
crossband is curved, the hyaline triangle is rather large and its 
apex crosses the second vein, and the apical spot is rather large 
occupying the apical part of the marginal and the first and second 
submarginal cells. Abdomen with a black spot beneath the 
scutellum widest before and connected with a black spot of the 
second segment. The black of the second segment is slightly 
emarginate behind and all but attains the posterior margin, and 
the broad yellow sides of this segment each inclose a small black 
dot. The remaining segments are black with a narrow serrate 
yellow posterior border, or there may be more or less separation 
of the black to form spots as in some of the related species. 
The male is much darker than the female. The thorax is 
black with gray stripes, the wing is black with a small spot at the 
apex of each basal cell, a suggestion of a hyaline spot on the mid- 
dle of the discal cell, and a hyaline triangle in all respects like 
that in the female. Parts of the fifth posterior, anal, and axillary 
cells are not so dark as the remainder of the wings. The abdo- 
men is black with gray posterior borders to the segment, and 
three rows of faint triangles. The venter is yellowish with a 
broad black stripe in the middle and less plainly marked narrow 
spots on each side. 
Adams has stated that the male of this species was described 
with some doubt by 'Williston, as the male of his pachycera. 
Chrysops sequax Williston. The species has somewhat the 
aspect of univittatus and striatus. Separated from the latter bv 
the hyaline triangle reaching or slightly transcending the second 
longitudinal vein, and the apical spot entering the first posterior 
cell. From the former by having four longitudinal black stripes 
on the abdomen instead of two. 
